Watch



April 3, 1945.

E. w. DRESCHER 2,372,771

- WATCH Filed Dec. 7, 1940 3 Sheets-Sheet 1 INVENTOR. I

ERAEST If MSG/ER A TTORNEYS.

E. w. DRESCHER 2,372,771

WATCH April 3, 1945.

5 Sheets-Sheet 2 Filed Dec. 7, 1940 lll llllllllllllllllllllll? INVENTOR. ERNEST W. DRESOHER A TTORNEYS.

E. w. DRESCHER WATCH April 3, 1945.

Filed Dec. '7, 1940 3 Sheets-Sheet I5 ww' NW? mm 3 5 v flm v N. v

IN VEN TOR.

ERNEST U. DM'SOI-IER BY 2?- A TTORNEYS.

.in a rotative direction.

v normal amplitude.

Patented Apr. 3, 1945 WATCH Ernest William Drescher, Lancaster, Pa., assignor to Hamilton Watch Company, Lancaster, Pa.

Application December 7, 1940, Serial No. 369,019

2 Claims.

This invention relates to a new and novel center sweep second and second setting timepiece.

One of the objects of this invention is to construct a sweep second watch having the second arbor positioned in the middle of the center stafl and so constructed and arranged that the watch will operate with the minimum amount of friction, can be repaired easily, and will be no thicker through its center than most watches not having a sweep second hand.

A second object of this invention is to so arrange the movingelements that there will be little or no possibility of these moving elements rubbing together.

A third object of this invention is to provide a flexible retaining spring 'so that damage to the extremely thin second arbor from dropping or rough handling will be eliminated or greatly reduced.

A further object of this invention is to construct a watch so that the second handmay be stopped at any point simply by pulling out the stem and the watch thereby set accurately not only so far as the minute vand hour hands are concerned but also in regard to the second hand.

Another object of this invention is to construct a rugged second setting device operated by the end of the stem so that the flexible element which it carries will bear only lightly against the side of the balance wheel and will not damage or break it or affect its rate in any manner whatsoever.

A still further object of this invention is to so construct th second setting spring that upon the stem being pushed into its normal operating or running position the spring will give the balance wheel a positive push and component of motion This push will bring the balance Wheel quickly to normal amplitude of motion and obviate the necessity of building up to Thus there is little or no irregularity in timing while awaiting the balance wheel to reach its full arc Of motion. Furthermore, the possibility of stopping the balance wheel on dead center is eliminated.

Other objects and advantages for this invention will be clearly apparent by reading the following specifications and the accompanying drawings.

Applicant desires to claim any or all advantages which are inherent in his device. It will be understood that the invention is susceptible of embodiment in various forms, one of which is illustrated in the accompanyin drawings, and that the structural details herein set forth may be varied to suit particular purposes without departing from the spirit of the invention. The invention may be clearly understood by referring to the drawings. However, I do not intend that the inventions should be limited by the drawings or any description, but on1y to be limited by the broadest possible scope of my invention. For simplicity the word watch appears generally throughout the specifications; however, this invention applies to any timekeeping or time recording mechanisms, for example, clocks, chronographs, recorders, etc.

In the drawings:

Figure 1 is a cut away plan view of the dial side of a watch showing the stem in its setting, or pulled out position;

Figure 2 is a view of the opposite side of a watch with the stem in the same setting or pulled out position, and also showing the second setting spring bearing against the balance wheel;

Figure 3 is a view of the rear of a watch similar to Figure 2 with the stem in its winding, running, or normal position and the second setting device in an inoperative position;

Figure 4 is a cross sectional view of the stem in the setting or pulled out position and showing certain details of construction of the second setting device;

Figure 5 is a view taken on the line Figure 2 and shows the running train and general organization and location of my invention.

Looking at Figure 5 which shows the general organization better than some of the other figures, numeral 1 designates the pillar plate, 2 the train bridge, and 3 the barrel bridge which is attached to pillar plate I.

Power stored in the mainspring housed in the barrel (not shown) is transmitted through the barrel wheel (not shown) to the balance wheel 30 in the following manner: To center pinion 6 on center stall 5, through center Wheel 7 to third pinion 9 on third staff 8, through third wheel Hi to fourth pinion l2 on fourth staff ll, through fourth wheel l3 to escape pinion IS on escape staff l4, through escape wheel l6 and pallet 49 to [balance wheel 30.

The third staff 3 has an end projection on which an extra third wheel and bushing or center second wheel and bushing H are attached. The center second wheel meshes with a center second pinion 18 mounted on a second arbor l9 which is positioned centrally of the center staff 5. A flexible shock absorbing spring 20 secured by screws 2| keeps the second arbor yieldably, but firmly in place.

Secured by a, light frictional fit to the upper end of the center staff 5 is a cannon pinion 26, on which an hour wheel 29 having an elongated neck is rotatably mounted. During the running operation the center staff and the cannon pinion turn as a unit, but during the setting operation, the cannon pinion is rotated on the center staff. Power is transmitted from center staff 5 and cannon pinion 26 through minute wheel 21 and minute pinion 28 mounted on stud 43, thence to hour wheel 29. The second hand 22, minute hand 23, and hour hand 24 are mounted on the upper ends of center arbor l9, cannon pinion 26, and hour wheel 29 respectively.

Figure 3 shows the watch in its winding, running, or normal operating position. The crown 42 and stem 39 are pushed inwardly so that the outer or upper clutch teeth on clutch 40 engage the clutch teeth on winding pinion 4| and the spur teeth on the winding pinion transfer energy to the mainspring through several intermediate elements. 1

Movement of the lower end of stem 39 causes an irregularly shaped lever or lever element 3! to move in an are around pivot 32 and cause second setting sprin 35, formed with an extremely flexible finger, to swing clear of balance wheel 39. The outer end of the post 33 is slotted and the second setting spring is peened preferably in the slot.

An open ended spring 38 is loosely positioned around post 37 and continually forces lever 3| to abut the inner end of stem 39. In order to retain laterally spring 38 around post 31 an outwardly extending lip is formed on the short end of the spring which engages in a recess formed in the pillar plate.

Pivot post 32 is shown as formed separately and inserted into an aperture in the pillar plate, while posts 33 and 31 are formed as one piece with thelever and'the pillar plate respectively. Obviously, the pivot post could be formed similar to posts 33 and 3! and vice versa.

A second setting cap 5! is positioned on a three point support comprising the upper ends of pivot 32, post 3'! and shoulder 35. The cap not only serves to hold the entire second setting mechanism in position, but also serves as an upper bearing 5?. for pivot 32 and prevents dust and dirt from accumulating on the working parts and hindering their operation. It is seen. therefore, that in this section of the pillar plate four elevations are provided, i. e., the base on which spring 38 rests, the projection on which the second setting lever is positioned, the shoulder on which the cap is supported, and the upper leveladiacent the cap which is of the same height as the top of the can when in assembled position.

The stem in its pulled out or setting position has another function in addition to stopping the balance wheel and second hand which is to permit the setting of the minute hand and the hour hand. When the stem is pulled out, setting lever M rides on the cam shaped. clutch lever 35 and forces the lower end of clutch 40 into engagement with the setting or intermediate wheel 5%. This wheel operates through elements 21 and 2G to set the minute hand, and through elements 21, 28, and 29 to set the hour hand.

A clutch lever spring 45 keeps the clutch lever against the setting lever. A setting cap spring 41 overlies the clutch lever and clutch lever spring and has formed at its one end a flexible extension 48 which acts as a spring to lock the stem in either a setting position or a winding position, and does not allow it to remain in an intermediate position.

The operation of the watch covered by this invention is as follows:

When it is desired to set the watch by means of radio time signals, chronograph, or any accurate timepiece, the crown 42 and stem 39 are pulled out. This action causes the spring 38 to swing the second setting lever 3i around post 32 and allows the flexible tip of spring 35 to engage gently either the balance screws or the balance wheel proper. An owner would normally set his watch when the second hand was in the 12 oclock position, but the balance wheel may 1 be stopped at any time simply by pulling out the stem. Also by rotating the stem when it is pulled out, the hour and minute hands can be set to any desired position. When the stem is pushed in, the watch will start correct to the second. One of the features of the invention is the fact that the lever arm of the second settin spring is so long and so flexible that there can be no possible chance of damaging any or the elements of the balance wheel assembly or its delicate adjustment. Another feature is the kick which the long lever arm of the spring is able to impart to the balance wheel when the stem is returned to its winding or running position. This action immediately sets the balance wheel running at its normal arc and accurate speed rather than necessitating an interval of time during which the watch will be running slower than usual until the balance wheel attains its normal, accurate speed.

This watch is particularly adaptable for doctors, radio technicians, laboratory and research engineers and others requiring split second performance.

This invention is a vast improvement over the old method commonly employed for setting the second hand of a watch which consisted of removing the bezel and crystal and by means of a finger, pencil or any other handy object holding the second hand until the desired time signal is heard, or moving the hand to correspond with the accurate chronograph. Obviously, perspiration from the finger and scratches from other objects mar the beauty of the dial, and likewise pressure on the second hand is liable to cause it to rub on the dial and mar iti or in other cases to stop the watch. An owner having his watch stop even if from this causewould erroneously assume. that the watch itself was poor. Also if the hand is moved very much it may become loose or damage the internal mechanism of the watch.

There have been other more convenient mechanical methods to set second hands, but these methods have not been entirely satisfactory. In some the stopping mechanism is complicated or cannot be fitted readily into a standard watch. In others the stopping element acts merely as a brake and does not push the balance wheel off dead center or serve to permit it toreach its maximum arc of motion immediately. In still others the stopping mechanism is not operated directly by the end of the stem, but by other unnecessary, added elements which complicate the mechanism, and make the device not only more expensive but also less rugged. In others the stoppage is eifected by a rigid body or flexible body on a portion of the balance wheel which will probably throw it out of true or out of round.

Briefly stated the advantage of this invention is its simplicity. There is practically no change in the movement over the conventional movement. An additional routing or cutting is made and a few additional elements are added without rearrangin the conventional watch movement. Likewise, a conventional, standard size watch case can be used without any modification whatever.

Although the action just described is recommended, it will be obvious that the shape and location of the various elements may be varied somewhat without departing from the spirit of the invention. It is not intended that applicant should be limited by his specific disclosure, and he is therefore claiming any obvious modifications which may be made of the broad idea.

What I claim is:

1. In a timepiece, a winding and setting stem movable longitudinally from winding position to setting position and back, an irregularly shaped lever member pivotally mounted and constantly urged into contact with the end of said winding and setting stem, a balance wheel, having the usual balance wheel screws, a spring finger secured at one end to said irregularly shaped lever and movable into contact with said balance wheel screws to prevent movement of said balance wheel upon movement of said stem, said spring finger being formed, at its free end, with a curve of sufficient radius to contact and bridge any two adjacent balance wheel screws.

2. In a timepiece, a winding and setting stem movable longitudinally from winding position to setting position and back, an irregularly shaped lever member pivotally mounted and constantly urged into contact with the end of said winding and setting stem, a balance wheel with the usual balance screws, 2, spring finger of a mass to be negligible when compared with the mass of the balance wheel, secured at one end to said lever and movable to engage said balance wheel screws and stop the balance wheel upon movement of the stem to setting position, the free end of said spring finger terminating in a curve of suflicient radius to contact and bridge any two adjacent balance wheel screws.

ERNEST W. DRESCHER. 

